High Energy seminar: "Precision Physics & Proton Structure at the LHC"

Johannes K. L. Michel (Massachusetts Institute of Technology)
- | David Rittenhouse Laboratory, 3C6

The LHC precision program critically relies on precise theory predictions for Standard-Model baseline rates to identify possible deviations due to New Physics and extract Standard Model parameters like the W mass. In this talk, I will present third-order QCD predictions for Higgs, Z, and W boson production at the LHC, with a particular focus on their transverse-momentum (qT) distributions, and including fully realistic fiducial acceptance cuts on their decay products. I will discuss how the resummation of large logarithms of qT, which is governed by the factorization of the cross section in terms of transverse-momentum dependent (TMD) PDFs, gives rise to a net resummation effect even in total cross sections in the presence of fiducial cuts. I compare our predictions for the Z boson transverse-momentum spectrum to high-precision measurements by the ATLAS and CMS experiments, discussing in turn the estimation of residual perturbative uncertainties, parametric uncertainties from the strong coupling and collinear PDFs, and uncertainties arising from the nonperturbative transverse structure of the proton as encoded in TMD PDFs and their evolution. I conclude by discussing synergies with the TMD program at the future Electron-Ion Collider at BNL and ongoing computational campaigns in lattice QCD.